NCT06552169

REgulatory T Cell Therapy to Achieve Immunosuppression REduction

The RETIRE Trial: A Randomized Phase 2 Trial of Adoptive Therapy With Treg Adoptive Cell Transfer (TRACT) To Prevent Rejection in Living Donor Kidney Transplant Recipients

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 34 (estimated)
• Sponsor: Singulera Therapeutics Inc. · Industry
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Not accepted

Summary

The goal of this multi-national, multi-center, open-label, randomized Phase 2 trial is to determine the safety and efficacy of administering expanded regulatory T cells (TRK-001) to prevent allograft rejection in living donor renal transplant recipients. Enrolled subjects will be randomized to one of 2 study arms: Arm 1 subjects will receive standard of care immunosuppression Arm 2 subjects will receive initial standard of care (SOC) immunosuppression and a single infusion of TRK-001. Three months after the transplant, Arm 2 subjects may be able to begin reducing their immunosuppression medication to a 1-drug regimen. The primary outcome measures of trial are to evaluate several components indicating immunologic problems with the transplanted organ at 1-year post-transplant and to evaluate the ability for the study subjects given TRK-001 to wean to a 1-drug immunosuppression regimen. All enrolled subjects will be followed for 5 years post-transplant.

Detailed description

This is a prospective, multi-national, multi-center, open-label, randomized Phase 2 trial to determine the safety and efficacy of administering autologous expanded regulatory T cells (TRK-001) to prevent allograft rejection in living donor renal transplant recipients. All subjects will be followed for 5 years post-transplant, comprising of a 2-year post-transplant follow-up period and a 3-year surveillance period. Subjects with end-stage renal disease undergoing a living donor kidney transplant will be enrolled into the trial as follows: Arm 1 SOC: Standard of care immunosuppression (N=14) Arm 2 TRACT/MONO: TRK-001 and initial SOC immunosuppression weaned to monotherapy (N=20) At Month 3 post-transplant, Arm 2 subjects will be further randomized prior to weaning to either mTOR or CNI monotherapy as follows: Arm 2A: TRACT/MONO mTOR (N=10) or Arm 2B: TRACT/MONO CNI (N=10)

Conditions

• Kidney Transplantation

Interventions

Type	Name	Description
DRUG	Arm 1: SOC (mTOR + CNI)	Subjects randomized to Arm 1 will remain on standard dual-immunosuppression therapy (CNI and mTOR) throughout the trial.
BIOLOGICAL	Arm 2A: TRACT/MONO mTOR	All subjects will be prescribed standard of care (SOC) immunosuppressive agents. Subjects randomized to Arm 2 will be maintained on the prescribed SOC immunosuppression (tacrolimus + sirolimus or everolimus) and have a single intravenous infusion of autologous, expanded Tregs (TRK-001) at Day +53 to +67 post-transplant. At Month 3 post-transplant, Arm 2 subjects will be further randomized to receive either: * Arm 2A: mTOR monotherapy or * Arm 2B: CNI monotherapy. These subjects will transition to the assigned 1-drug immunosuppression regimen beginning at Month 3 post-transplant. Weaning must be completed by 12 months post-transplant. Subjects in Arm 2 will undergo leukapheresis to collect peripheral blood mononuclear cells required for the cellular product.
BIOLOGICAL	Arm 2B: TRACT/MONO CNI	All subjects will be prescribed standard of care (SOC) immunosuppressive agents. Subjects randomized to Arm 2 will be maintained on the prescribed SOC immunosuppression (tacrolimus + sirolimus or everolimus) and have a single intravenous infusion of autologous, expanded Tregs (TRK-001) at Day +53 to +67 post-transplant. At Month 3 post-transplant, Arm 2 subjects will be further randomized to receive either: * Arm 2A: mTOR monotherapy or * Arm 2B: CNI monotherapy. These subjects will transition to the assigned 1-drug immunosuppression regimen beginning at Month 3 post-transplant. Weaning must be completed by 12 months post-transplant. Subjects in Arm 2 will undergo leukapheresis to collect peripheral blood mononuclear cells required for the cellular product.

Timeline

• Start date: 2025-06-13
• Primary completion: 2027-12-01
• Completion: 2031-12-01
• First posted: 2024-08-13
• Last updated: 2026-02-17

Locations

7 sites across 2 countries: United States, Taiwan

Regulatory

• FDA-regulated drug study